PLS62-W very slow data receiving with AT^SISR | Telit Cinterion IoT Developer Community
August 5, 2020 - 11:01pm, 728 views
We are trying to receiving TCP data from PLS62-W chip to our MCU using AT command AT^SISR, but got very slow speeds (less then 1 KB/s).
Investigating this, showed that PLS62-W response with quite huge delays:
It takes about 40+ ms to answer on AT^SISR=0,128 with ^SISR:0,128 and then another ~160ms to transmit data and answered with final OK.
UART baudrate is 115200, but we tried 460800 also - it speed up everything in average just for 5ms ***.
Also to exclude our program influence, we did try same thing with PLS62T-W external terminal sending AT^SISR=0,128 from Windows PuTTY terminal logging timed data and got same result (single LF - is pasted by PuTTY on logging):
As we can see 128 byte data transmission itself no so much delayed after ^SISR: 0,128, but final OK is gotten really latter.
It's quite surprisingly to see these from 4G ****m.
What is the reason of this issue? Thanks in advanced for help!
If you need better performance please try transparent ****. Then after connection establishment and switching over to transparent **** your application can just send and receive data without additional AT commands. Please refer to AT commands specification for details.
The performance of data transfer with SISR and SISW will always be slower as there is some overhead related to AT commands execution ***** and the recommended delays between each command execution. To optimize this use case you can request more bytes (up to 1500) with each SISR call.